CVE-2026-7541 — Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via unauthenticated API endpoint
A denial of service vulnerability was identified in GitHub Enterprise Server that allowed an unauthenticated attacker to cause service disruption by sending crafted requests with deeply nested JSON payloads to an unauthenticated API endpoint. The endpoint parsed user-controlled JSON request bodies without size or depth limits, causing excessive CPU and memory consumption. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.20.2, 3.19.6, 3.18.9, 3.17.15, and 3.16.18. This vulnerability was reported via the GitHub Bug Bounty program.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.7% (30-day exploitation probability)+8
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Github Enterprise Server).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Github | Enterprise Server | < 3.16.18≥ 3.17.0 and < 3.17.15≥ 3.18.0 and < 3.18.9≥ 3.19.0 and < 3.19.6≥ 3.20.0 and < 3.20.2 | Vulnerable | NIST National Vulnerability Database |
| Github | Enterprise Server | ≥ 3.16.0 and ≤ 3.16.17≥ 3.17.0 and ≤ 3.17.14≥ 3.18.0 and ≤ 3.18.8≥ 3.19.0 and ≤ 3.19.5≥ 3.20.0 and ≤ 3.20.1 | Vulnerable | CVE Program (cve.org) e CISA ADP |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.3 | CVSS 4.0 | Medium | — | — | product-cna@github.com via NIST National Vulnerability Database |
| 6.3 | CVSS 4.0 | Medium | — | — | GitHub_P via CVE Program (cve.org) e CISA ADP |
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CWE-770 · Allocation of Resources Without Limits or Throttling
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.66%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · github/enterprise server
- SSVC assessment updated
- Record published
- CVSS changed · 7.5
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
5 on the record
- docs.github.com/en/enterprise-server@3.17/admin/release-notes
- docs.github.com/en/enterprise-server@3.19/admin/release-notes
- docs.github.com/en/enterprise-server@3.20/admin/release-notes
- docs.github.com/en/enterprise-server@3.16/admin/release-notes
- docs.github.com/en/enterprise-server@3.18/admin/release-notes
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-96890 Server-Side Request Forgery vulnerability was identified in GitHub Enterprise Server that allowed requests to attacker-controlled internal hosts 9d
- Medium CVE-2026-103620 Missing authorization in GitHub Enterprise Server allowed repository writers to replace default branches via GraphQL 9d
- High CVE-2026-15996 Uncontrolled Recursion in Github Enterprise Server Aug 5, 2026
- Critical CVE-2026-17556 Path Traversal in Github Enterprise Server Aug 5, 2026
- Medium CVE-2026-15783 Missing Authorization vulnerability was identified in GitHub Enterprise Server that allowed reading private repository metadata via delegated bypass rule suites Jul 17, 2026
- Medium CVE-2026-15007 Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via deeply nested YAML in release notes configuration Jul 17, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-7541 is "Denial of service vulnerability in GitHub Enterprise Server allowed service disruption via unauthenticated API endpoint", rated High. It affects Enterprise Server (Github); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 0.66% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
Comments
Moderated technical discussion. Read the community guidelines.
No comments yet.
Sign in or create an account to comment and suggest corrections.